Yo-yo Materials
Over the last centuries different materials have been used for making yo-yos, specifically yo-yo halves. This page deals with their history and yo-yoing properties. For axle materials see Axles. Wood Yo-yos were - if we ignore some of the ancient Greek ones made of clay and the traditional Philippine yo-yos made of caribou horn - originally made out of wood. Since yo-yos are usually subjected to lots of physical abuse the woods used are most often hardwoods. For its even density, maple has become the primary choice here. Beech is also sometimes seen. To add a nice color effect, plywood also is used, each layer dyed differently, looking like a rainbow. This technique was pioneered by Hummingbird. Advantages: * Abundantly available * Can be easily turned * Looks and feels nice Disadvantages: * Uneven density, making a yo-yo often slightly wobbly * Difficult to process other than by turning. While it is technically possible to machine a starburst into a wooden yo-yo, it is usually not done for reasons of economy. * Insufficient density for modern yo-yo shapes Plastic Since the advent of thermoplastics (i.e. plastics that can be molded by melting them), these materials have been widely used to make yo-yos. Advantages: * Cheap * Easily molded into nearly any shape * Easily dyed any color * Good density * Has good rotation and stability Disadvantages: * Molding often leaves sharp edges * Difficult to mold without enclosing gas bubbles Polycarbonate Polycarbonate is a very strong plastic used in many injection molded yo-yos. It has high strength to weight ratio and can flex under impact. Many yoyos are made from this plastic due to its ease of use, low cost and existing worldwide manufacturing base. It is often referred to as 'polycarb'. Some examples of polycarbonate yo-yos include the Duncan Freehand series. A large proportion of current YoYoJam models are also polycarbonate. Enyo is a trademarked polycarbonate with suspended holographic foil particles that glimmer strongly in direct sunlight. Clear yo-yos are usually polycarbonate due to the natural clear quality of the plastic along with its high strength/weight ratio. Colored polycarbonate yo-yos are made by adding coloring to the plastic. Sprite trademarked yo-yos often have bubbles in them which is made by adding a powder, often baking soda, to the mix during injection that produces carbon dioxide which expands in the polycarbonate making a bubble. Polycarbonate has some drawbacks when used in the production of yo-yos. It will crack when dimensions are too thin and when exposed to even small amounts of solvents it crazes (surface cracking), becomes brittle and yellows as the solvent degrades the plastic. ABS (acrylonitrile butadiene styrene) ABS is a strong, lightweight and inexpensive plastic used for some yo-yos. It is not rigid enough to be successfully used in places where strength, weight and rigidity are priorites such as standard sized rim-weighted yo-yos. It is used in less expensive yo-yos such as the modern Duncan Wheels (vintage models are polycarbonate and sought after by modders). It lends itself to very well to inexpensive mass produced yo-yos that can have thicker dimensions and do not have rim weighting. It is easily scratched and does not machine well due to a low melting point. Advertising yo-yos are often made from ABS. Delrin/Celcon Delrin and Celcon are trademarks for nearly identical polyacetal plastics, which are machineable like aluminum. Polyacetal is a lightweight, durable, low wear, and low friction plastic originally developed by Dupont in the 1950s as a metal substitute. It is not as prone to ding or scratch as aluminum while retaining many of the qualities desired in a machineable material. The Silk by Eric Wolff, the Milk by Paul Yath, the Lucha Libre by Throw Down, and the Gung-Fu by Death By Yo-Yo are examples of yo-yos that are made of this material. Some polyacetal yo-yos, such as those already mentioned, are machined like metal yo-yos while others, such as the Lyn Fury and the KickSide, are injection molded from Celcon. Polyacetal has also been used in the hubstacks of YoYoFactory yo-yos, such as the G5. Heavy Gravity Heavy Gravity is a composite material used by YoYoJam, made by saturating plastic with metal powder either before or during the injection molding process. It is much more dense than plastics typically used in yo-yo manufacture. Because of this, it allows for rim weighting at a cheaper price than with metal rims, since it is produced by injection molding rather than machining. It also allows greater flexing versus metal, which likely reduced stresses in other parts of the yo-yo during impacts. Heavy Gravity was used in the production of the SpinFaktor HG, Black Gold, the Copperhead series, SpinFaktor HG Xtra, Triple Jam, Relic, Matador, and the K-OS series. Eventually, changing costs rendered the material too expensive without substantially altering the retail price, so production of yo-yos with Heavy Gravity has ceased after the K-OS Extreme. Aluminum While other metals have been used to add rim weight to yo-yos, none was so often used as aluminum. Ever since Tom Kuhn made his first Silver Bullet, yo-yos made of aluminum have been successful in production. Advantages: * Attractive * Slightly more dense than most plastics (and won't have air bubbles like some plastics resulting in smoother play) * Usually smoother and has less friction than plastic giving better grinds * Anodization allows many different colors to be made Disadvantages: * Susceptible to corrosion * Expensive compared with plastic alternatives * It is easy to get dings or scratches if it makes contact with rough surfaces * Resonates easily, resulting in an annoying ringing sound during play Titanium Titanium is a relatively rare yo-yo material because its cost makes the yo-yo's retail price prohibitive, and it is significantly more difficult to machine. Usually, titanium is only used in a small quantity, for example, for the weight rings in yo-yos such as the YoYoJam Night Moves and YoYoFactory Catch 22, or for the axle, such as the Oxygene Oxy3, Oxygene Oxy4, Oxygene Oxy 3vo, Oxygene Oxy 5, and the Oxygene Oxy "6" (small prototype run released in early 2011 in Europe). However, the relative number of titanium yo-yos since the year 2000 has increased significantly. For example, here is a list of yo-yos where the body is solid titanium (but other parts, such as the center, may be made of stainless steel or copper): Oxygene Oxy Ti (2009), Oxygene Oxy Ti 2011, NorthSpin Aurora, Vs. Newton Yo-Yo Concepts Ti Walker, YoYoJam Titan Gold, Kyo TiPhiter 1, Kyo TiPhiter 2, Kyo Tiraid, One Drop Sovereign, Anti-Yo BSP, Russell Andert Derti, YoYoRecreation Dazzler, etc. VsNYYC has stated it will produce another titanium yo-yo in 2011. OD states that the next titanium yo-yo they make will be a different model from the Sovereign. Titanium produces a significantly different sound than aluminum when it resonates after being struck. Pros: * As strong as steel, but lighter, so it is possible to increase a yo-yo's rim weight beyond that of aluminum. * Raw titanium finish does not oxidize to a dull color as fast as Aluminum * Resistant to scratches * Resistant to corrosion * Sparks when "walked the dog" on concrete for a neat effect Disadvantages * Significantly more expensive than aluminum ($100 vs $300, Aluminum vs. Titanium) * Anodize finishes are limited in comparison to aluminum, since color changes are accomplished by increasing the thickness of the native oxide layer. Magnesium Magnesium is another rare yo-yo material with properties similar to aluminum. It strong and light, and often used in race car wheels and disc brakes. The Duncan Freehand Mg was the first be made from a magnesium alloy, and has so far been followed only by the General Yo Magnum. Advantages * Strong * Light * Can be machined to very precise tolerances * Can be anodized or powder coated Disadvantages * Expensive * Harder to work with than aluminum * WARNING: Flammable in powder form! Corian Corian is the same material that countertops are made from. There are currently no commercially produced yo-yos in this material, but a few prototypes and one-off yo-yos had been made of this material. Steel Steel is a relatively rare material in yo-yo production, and has been used to create the ILOVEYOYO St. Eel and the rims of the Northern Spin Helix. Advantages *Heavy enough to make an undersized yo-yo (such as the YoYoFactory Mighty Flea) feel like a larger yo-yo *Attractive *Can be anodized *Dings and dents less easily than aluminum Disadvantages *Too heavy for use in a full-sized yo-yo *Susceptible to rusting Category:Yo-yo components